Lights Flicker When Dehumidifier Turns On? Here’s the Fix!
That momentary dimming or flickering of your lights when the dehumidifier kicks on can be unsettling. Is it a minor annoyance or a sign of a more significant electrical problem? You’re not alone in wondering about this common household issue.
Fortunately, in many cases, this phenomenon is relatively harmless. However, it can sometimes point to underlying electrical issues that need attention. This comprehensive guide will illuminate the causes and provide clear, actionable solutions.
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Understanding the Power Draw of Your Dehumidifier
Your dehumidifier is a powerful appliance. When it starts up, its compressor requires a large, initial surge of electricity. This is often referred to as “inrush current” or “locked rotor amps” (LRA).
This sudden, high demand for power can cause a temporary drop in the voltage available to other devices on the same circuit. Your lights are sensitive to these voltage fluctuations, which results in the brief flicker you observe.
The Science Behind the Flicker: Voltage Drop Explained
Think of your home’s electrical system as a water pipe. When you suddenly open a large valve (the dehumidifier turning on), the water pressure (voltage) momentarily drops for all other faucets (your lights) connected to that pipe.
This voltage drop is usually brief and resolves once the dehumidifier’s motor is up and running. However, if the flicker is severe or persistent, it’s time to investigate further.
Common Causes for Flickering Lights
Several factors can contribute to your lights dimming when the dehumidifier starts. Identifying the root cause is the first step toward finding the right solution. Let’s explore the most frequent culprits.
Overloaded Electrical Circuit
One of the most common reasons for flickering lights is an overloaded circuit. Your home’s electrical system is divided into circuits, each protected by a circuit breaker with a specific amperage rating (usually 15 or 20 amps).
If your dehumidifier is plugged into a circuit that’s already powering other high-demand appliances like a refrigerator, microwave, or space heater, the combined load can exceed the circuit’s capacity. This leads to a more pronounced voltage drop when the dehumidifier starts.
Running too many devices on a single circuit is a frequent issue. You might need to redistribute your appliances to balance the electrical load.
Outdated or Faulty Wiring
Older homes, in particular, may have wiring that isn’t up to modern standards. Over time, electrical connections can become loose, or the wiring itself can degrade. This creates higher resistance in the circuit.
When the dehumidifier draws its initial surge of power, this high resistance can cause a significant voltage drop, leading to noticeable flickering. Loose connections at outlets, switches, or in the electrical panel are a serious fire hazard and should be addressed immediately.
Shared Circuits with Major Appliances
Ideally, major appliances should be on their own dedicated circuits. Sharing a circuit between your lighting and a powerful appliance like a dehumidifier is a recipe for flickering.
Modern electrical codes often require dedicated circuits for appliances that draw a significant amount of power to prevent these very issues. If your lights and dehumidifier share a circuit, this is likely the primary cause of the problem.
Issues with the Dehumidifier Itself
While less common, the problem could lie with the dehumidifier. An aging or failing compressor motor can draw more current than it should upon startup, exaggerating the voltage drop.
If the flickering is a new phenomenon or has recently become worse, and you haven’t changed anything else in your home, the appliance itself could be the culprit.
Actionable Solutions: How to Stop the Flickering
Now that you understand the potential causes, let’s move on to the solutions. Some of these are simple fixes you can try yourself, while others will require the expertise of a qualified electrician.
Step 1: Isolate the Problem
First, try plugging the dehumidifier into a different outlet on a completely different circuit. You can identify circuits by checking the labels on your electrical panel. If the flickering stops, you’ve confirmed the issue is with the original circuit being overloaded.
This is a crucial diagnostic step. It helps you determine whether the problem is localized to one area of your home or is a more widespread issue.
Step 2: Balance the Load
If you’ve identified an overloaded circuit, the solution is to redistribute your appliances. Map out which outlets belong to which circuits and move some high-power devices to less-burdened circuits.
Avoid plugging your dehumidifier into the same circuit as other major appliances. This simple change can often resolve the issue entirely.
| Problem | DIY Solution | When to Call a Pro |
|---|---|---|
| Overloaded Circuit | Move the dehumidifier to a different circuit. Unplug other devices from the same circuit. | If flickering persists or you need a new dedicated circuit installed. |
| Faulty Wiring | Check for visible signs of damage at the outlet (discoloration, melting). | Immediately. Do not attempt to fix wiring yourself. This is a job for a licensed electrician. |
| Shared Circuit | Use a different outlet on a dedicated circuit if available. | To have a new dedicated 20-amp circuit installed for the dehumidifier. |
| Appliance Issue | Test the dehumidifier on multiple circuits. If the problem follows the appliance, it’s likely faulty. | If the appliance is under warranty, contact the manufacturer. Otherwise, consult an appliance repair technician. |
| Inadequate Electrical Service | Notice other signs like frequent breaker trips or dimming lights throughout the house. | For a professional load calculation and to discuss upgrading your service. |
Step 3: Consider a Dedicated Circuit
The best long-term solution for a powerful appliance like a dehumidifier is to have it on its own dedicated circuit. This ensures it has all the power it needs without affecting other devices in your home.
A licensed electrician can easily install a new circuit and outlet for your dehumidifier. This is a relatively minor investment that can improve the safety and performance of your entire electrical system.
When to Call a Professional Electrician
While some troubleshooting can be done on your own, certain signs indicate it’s time to call in a professional. Electrical work is not a DIY project; it requires expertise to ensure safety and code compliance.
Persistent or Widespread Flickering
If the lights flicker throughout your entire house, not just in one room, it could signal a problem with your main electrical service or the connections in your breaker panel. This could also be a symptom of a partial power outage, which requires immediate attention.
Widespread dimming can indicate that your home’s overall electrical service is insufficient for your needs. An electrician can perform a load calculation to determine if you need an upgrade.
Signs of an Inadequate Electrical Service
Does your home still have an older, smaller electrical panel? You might be wondering what 150 amp service is and if it’s enough for a modern household’s demands.
If you frequently trip breakers or your lights constantly dim when large appliances run, it may be time to consider an upgrade. Consulting an electrician about the benefits of a 150 amp vs 200 amp service can help you decide on the right choice for your home’s future electrical needs.
Other Warning Signs
If you notice any of the following, turn off the circuit at the breaker and call an electrician immediately:
- A burning smell coming from an outlet or your electrical panel.
- Outlets that are hot to the touch.
- Discolored or melted outlet covers.
- Buzzing or crackling sounds from outlets or switches.
These are all signs of dangerous electrical faults that could lead to a fire. Do not ignore them.
Conclusion: Ensuring a Safe and Stable Electrical System
Flickering lights when your dehumidifier turns on are often just a sign of a temporary voltage drop on a heavily loaded circuit. By taking simple steps like moving the appliance to a different circuit, you can often resolve the issue.
However, it’s crucial to recognize when this flickering is a symptom of a larger problem. Pay attention to your home’s electrical system, and never hesitate to call a licensed electrician if you suspect faulty wiring or an overloaded service. Ensuring your electrical system is safe and robust is one of the most important things you can do for your home and family.
